It's been 65 years since a nuclear weapon was used in war. Yet the Doomsday Clock still stands at six minutes to midnight, and there are more than 20,000 nuclear warheads in the world. Here's where they are.

The exact status of the world's nuclear weapon supply is only known through educated guesswork and occasional information leaks. Nations with nuclear weapons hold their locations and attributes close to the vest at best (the U.S., Britain) or cloak them almost completely in utter secrecy (North Korea, Israel).

Two nations have more nuclear weapons than all other nations combined: the U.S. and Russia. If you subscribe to George Carlin's "Bigger Dick Foreign Policy Theory," you can infer that these are the two most insecure nations in the world, with roughly 10,000 nuclear weapons each, several thousand of them operational. Using the weapons stores from these two nations alone, we can still obliterate all life on Earth several times over without much effort.

Who else has nukes, and who will get them soon?
The chief treaty limiting nuclear weapons is the Nuclear Non-Proliferation Treaty, first drafted in 1970. While 189 nations have signed the treaty, only five of them are known nuclear states: the U.S., Russia, the United Kingdom, France and China. The UK, France and China are thought to have a few hundred operational weapons each. The treaty forbids giving nukes to nations that don't have them or helping them develop their own. It also encourages disarmament and allows for the peaceful use of nuclear technology. The good news is both the U.S. and Russia have dismantled thousands of nuclear weapons since the 1990s, thanks in part to the treaty. There's still plenty of bad news though.

There are quite a few nations with nuclear weapons that aren't part of the treaty. India and Pakistan are known to have nuclear weapons, each holding a few dozen. Israel steadfastly refuses to confirm or deny that they have nukes, but analysts are certain they do, and estimate they hold as many as 200 of them. North Korea, once a signatory to the treaty, withdrew from it and has conducted two nuclear tests. However, it is believed they have fewer than 10 warheads and no operational method of delivering them.

Who hosts their nukes in foreign countries?
Many other nations have had access to nuclear weapons in a variety of ways. The U.S. positioned nuclear weapons in countries like Turkey, Belgium and Canada, claiming this circumvented treaty restrictions because the weapons remained under U.S. control. Former Soviet republics Kazakhstan, Belarus and Ukraine inherited nuclear weapons when the Soviet Union collapsed (5,000 of them, in Ukraine's case). Since then, all of those weapons have been dismantled or transferred to Russia.

Does anybody ever go from being a nuclear power to a non-nuclear power?
South Africa is an interesting case in that they developed their own nuclear weapons, then signed the treaty in the early 90s and completely dismantled their entire nuclear arsenal. Meanwhile, Libya was found in violation of the treaty and their secret nuclear weapons program was investigated and shut down in 2003. Iran's nuclear program has been suspected of being used for weapons development and subject to sanctions by the U.S., but the U.N. has taken the position that it is better to keep Iran working within the framework of the Non-Proliferation Treaty than to alienate the nation, and declared their program to fall within the legal bounds of the "right to peaceful nuclear research."

Unfortunately, the danger isn't restricted to the big names in the "nuclear club." In the recent documentary Countdown to Zero, director Lucy Walker reports that dozens of nations now have access to nuclear fuel which could potentially be weaponized, and there are verified instances of smugglers trying to sell weapons grade uranium to terrorists. Perhaps even worse, access to nuclear launch codes is less restrictive than during the Cold War, with lower-level officials having the power to launch devastating nuclear attacks.

We've settled into complacency regarding the nuclear nightmare. Walker wondered in a CBC interview, "Is it just ignorance and a misunderstanding that they went away? Is it exhaustion? Is it that we're worried about climate change, and we can only think of one thing at a time?"